The invention relates to an electromagnetically-operated multi-way valve, especially of the type where more than one valve arrangement is associated with an armature configuration, whereby the efficient movement of the armature configuration brings about a timely switching action to the number of valve-operating positions.
One type of multi-way valve is known from the German Patent DE-OS No. 2403770. This known electromagnetically-operated multi-way valve exhibits two valve seats, located opposite one another in a valve housing, which form two valves with two corresponding valve bodies (inlet valve--outlet valve). The two valves are located inside an armature, which can be axially displaced in the housing of the multi-way valve against a return force, and which is surrounded by a coil. The return force for the armature is provided by a first spring braced against the valve housing and acting directly on the armature, and a second spring located between the two valve bodies. The second spring thereby primarily has the function of a spreader spring, which pushes the two valve bodies in opposite directions. The first spring, on the other hand, acts as the main spring, the force of which must be overcome when the coil is excited by the magnetic force acting on the armature. In the armature, there is a bracket for the two valve bodies. The bracket is designed so that the two valve bodies can be moved by a predetermined distance in the axial direction in their mountings on the bracket.
When there is no power to the coil, the inlet valve is in the open position and the outlet valve is in the closed position. If a partial current is imparted to the coil, the armature is moved against the force of the first spring toward the inlet valve seat. The inlet valve body, acted on by the second spring, is pushed against the inlet valve seat. The inlet valve is now closed. The outlet valve remains closed on account of the force of the second spring acting on the outlet valve body. If the current in the coil is increased, then the armature is moved by the stronger magnetic force against the force of the first spring farther toward the inlet valve seat. The outlet valve body is lifted up from the outlet valve seat by the bracket which simultaneously acts as a driver against the force of the second spring. The outlet valve is now open and the inlet valve remains closed.
This known current-controlled, electromagnetically-activated multi-way valve has the disadvantage that it is relatively complicated. Since the armature is used to activate both valves (inlet valve and outlet valve) and forms one component together with the bracket for the valve bodies, the valve bodies themselves and the second spring, it exhibits a large mass to be accelerated, which has a negative effect on the switching action (relatively large switching hysteresis). To activate this multi-way valve, relatively large magnetic forces are necessary, i.e., relatively high currents.